This invention relates to centrifugal pumps and to an improved connection structure between a driver and the pump; and to an improved arrangement of impeller position adjustment means in such pumps.
Typically, centrifugal pumps have three components arranged between the driver and the pump housing. These components consist of a motor adapter frame, the bearing housing and the pump adapter frame. Heretofore these components have been separately formed and installed together by bolting as shown in U.S. Pat. No. 4,439,096, issued Mar. 27, 1984.
As also shown in U.S. Pat. No. 4,439,096, impeller position adjustment means are provided. This reference describes a centrifugal pump having a bladed impeller in a stationary pump casing, the leading edges of the blades being adjacent a first radially extending wall of the housing. The pump has a rotatable shaft on which the impeller is mounted, a bearing cartridge holding a thrust bearing therein for rotatably holding the end of the shaft which is opposite the impeller, and adjustable fastening means for connecting the bearing cartridge to the bearing housing. The impeller, shaft and bearing cartridge together are adapted for axial adjustment upon axial adjustment of the fastening means, the fastening means having at least two threaded bolts projecting from the bearing housing in a direction parallel to the axis of the shaft, and having reference nuts for fixing the position of the bearing cartridge on the bolts. The reference nuts have marks at regular angular intervals, and at least one reference mark on the bearing cartridge adjacent each reference nut cooperating with the marks on the reference nuts for indicating the axial position of the impeller with respect to the pump casing. However, the bolts and reference nuts are exposed to environmental and weather conditions.